Subject: Whats this little bug?
Location: 95762 CA, US
January 13, 2014 11:06 pm
Mid January in Northern California near Sacramento. These little bugs have been bugging my plants in an aquaponics system in a hoop house. They also seem to leave webs of some kind behind. Any help would be greatly appreciated! thanks
Signature: Chris Haislet

Drain Fly

Hi Chris,
This appears to be a Drain Fly or Bathroom Fly in the genus Clogmia in the Moth Fly family Psychodinae. We typically get identification requests regarding Drain Flies from homemakers who are perplexed by their appearance in bathrooms and kitchens. In the home, the larvae live in the sludge that collects in drains and pipes. According to BugGuide: “Larvae feed on algae, fungi and bacteria in sewage and organic sludge; adults feed in polluted water and on flower nectar.” We don’t believe they have any interest in your plants, but rather in the hydroponic system itself which may need some cleaning and maintenance. We are not convinced the webs you mentioned are related to the Drain Flies. BugGuide also notes: “In the home, females lay irregular masses of 30-200 eggs in the organic gelatinous film lining drains, particularly in bathtubs and showers; eggs hatch 32-48 hours after being laid, when ambient temperatures are 70ºF (about 20ºC), and larvae pupate 9-15 days later; pupa stage lasts 20-40 hours; development time from egg to adult is 7-28 days, depending on temperature and food availability; adults live for about two weeks” and “Larvae play an important role in purifying sewage in industrial sewage treatment plants. Adults are very weak fliers, covering only a few feet at a time in short erratic flights.”

The Amazing Replicating Moth?
Location: Washington DC
March 24, 2012 8:45 am
Dear WTB,
So, this particular creature population has been living with us for quite some time- since last summer. At first, they were not much of a problem and we didn’t mind coexisting (especially considering our battle at the time with fungus moths in our plants- ARG!) Anyway, things have gotten way out of control with these little moth-like bugs. Hundreds populate our home on a daily basis. Regardless of whether I decide to kill a bunch or not, they do not seem to live very long to begin with, but always return in greater numbers. I am hesitant to call the exterminator because they charge such ridiculous rates just for a basic assessment. In my searching on the internet, people insist that they are cupboard moths, but they don’t look like them and do not reside in our cupboards at all. They can be found all over the windows, wall and by lights. Our neighbors don’t seem to have them. Do you have any pointers for helping me to understand what they are, how to find the source and take care of them? Thanks.
Signature: Travis

Bathroom Fly

Hi Travis,
The Bathroom Fly is a common household pest that belongs to the family of Moth Flies, hence your confusion as to its identity. Indoors Bathroom Flies breed in the sludge that accumulates in drains, and that is where the larvae can be found. Exterminating the adults will not help with your problem. You need to get to the larvae. Pouring chlorine bleach down the drains once a week may help.

Daniel,
You are nothing short of amazing! Thank you sooooo much. I will give your idea a shot and let you know of our progress. My only question is whether is is more likely that the moths are coming from a drain outside or are they originating from indoor clogged drains? If outside, I am at a loss. However, they seem to be outside the house often enough. More often inside though, I must admit. Thanks for your thoughts. Bleach in the drains tomorrow and we’ll see.
Thanks, Travis

Chlorine bleach?!
March 27, 2012 7:39 am
Daniel:
Advocating the use of chlorine bleach is to my mind akin to Unneccesary Carnage of the environment. Chlorine is bad stuff. I wonder if there are less harmful ways to deal with Bathroom Flies? Thanks, Dave Fallow
Signature: Dave Fallow

Thanks Dave,
Many products that we use on a daily basis, including ones to clean our homes, its furnishings and even ourselves, are harmful to the environment, and moderation in our habits is about the best that we can hope to do at this point since so much damage has already been done to this fragile planet. Perhaps a better response would have been that the Bathroom Flies, though a nuisance, are basically harmless.

Related posts:

What Is This Fly?
Location: Toronto, Canada
May 18, 2011 8:14 pm
I work in a medical office on the second floor and we have large windows. There are a few houseplants at the window. I noticed these small flies every day. They keep coming from somewhere, but our windows don’t open so they may live inside the building. They are very sluggish, I can pick them up with my fingers or hands. They don’t fly away like normal flies. I find many of them sitting by the window, usually dead and drying up. I can’t seem to figure out what they are, and where they are coming from. Can you please help?
Signature: Eddie

Bathroom Fly

Hi Eddie,
This is an amazingly detailed image of a Bathroom Fly. Bathroom Flies breed in the sludge that accumulates in drain pipes. They are also called Drain Flies or Moth Flies.

Identification
Location: west coast Tampa Florida
January 21, 2011 8:52 pm
Hi
I find these in my bathroom only. The bathroom has a exhaust fan in the ceiling and a drain in the shower. The size is between an eighth and three sixteeths of an inch.
Richard
Signature: Thanks in advance

Bathroom Fly

Hi Richard,
Interestingly, you had all of your answers built into your submission. This is a Bathroom Fly in the Moth Fly (how you labeled your photo) family Psychodidae. They breed in the sludge that forms in pipes and the adults can become quite plentiful in rooms with plumbing that needs to be cleaned out.

What the heck might this be
Location: Queensland. Au
September 18, 2010 12:11 am
Hi guys,
Thanks for the info on the lacewing nymph. Now to this one. It is only about 3mm body length, has antennae and legs like a moth but appears to only have two wings like a fly. Do you have any idea on what type of thing it may be?
The book is looking good, hope it sells really well.
Signature: aussietrev

Bathroom Fly

Hi Trevor,
This is a Bathroom Fly or Drain Fly, probably in the genus Clogmia in the Moth Fly family Psychodinae. According to BugGuide: “Adults often found around sewage installations, in public washrooms, and bathrooms in homes, and are attracted to light; larvae live in organic sludge that forms on inner surfaces of drains and sewage pipes; pupae occur on the surface of the organic film that the larvae have been living in.“

bug found in the mens washroom at work
July 13, 2010
Hello – a very silly request so I apologize in advance – but there’s a fly in one of our washrooms here at work that i’ve never seen before. Googling does not get me the results I hope for.
Bored at work
Toronto, Canada – 6th floor

Bathroom Fly

Dear Bored at work,
We wondered if perhaps the problem you had identifying this Bathroom Fly (yes that is its name) had anything to do with the semantics of the word “washroom” as opposed to bathroom, so we did a search of “fly” and “washroom”. On the first page of possibilities was a website with an image of your creature. Bathroom Flies in the subfamily Psychodinae are also known as Moth Flies, Drain Flies, Sewage Flies or Filth Flies according to BugGuide.